Do you want to buy a bike and are you not sure which type and size to choose? We have prepared a detailed guide for you to help you choose the right bike size and type for adults and children.
Criteria before purchasing a bicycle
Before you choose the right bike size, some criteria need to be clarified. The main role of the choice is played by the type of bicycle, which is derived from the terrain in which one is supposed to move mainly. From this point of view, there is no 100% universal bicycle. Each bike is suitable for a specific type of terrain, and everything must be carefully considered. The chosen type of bicycle, as well as its quality and price should therefore always take into account the kilometres travelled per year, the riding style, as well as the predominant terrain.
The choice must therefore take into account the following:
- Bicycle type (mountain bike, cross bike, trekking bike, …)
- Material of the frame and quality of used components
- Frame size (compared to height)
- Components (equipment of the bicycle)
- Total price-performance ratio
If you don’t choose the right bike size, as well as unfavorable adjustment of the seat, can significantly worsen your overall driving comfort, and in a longer-term horizon back, as well as joint pain of upper and lower limbs, or other body parts to cause.
What type of bike?
Aluminium, magnesium, scandium, carbon, steel and rarely titanium are used for frame production. The following table explains the properties of individual materials:
Aluminum – the advantage of the frames made of aluminium alloys is usually their low weight and the side stiffness of the frame. Their disadvantage, on the other hand, is low or no elasticity and a higher price compared to steel. An essential element for improving the properties of the aluminium frames is the profiling (forming) of the tube. The aluminium frames are referred to as aluminium (possibly with the type designation – 6061, 7005, 7020, etc.), Allux, Alloy, Dural, Easton, Alutron, etc. The price and weight of these frames differ depending on the use of different types of aluminum alloys and technologies.
Carbon – is created by laying the layers of the carbon fabric and the binder in special shapes and their baking under pressure and with suctioned air. This manufacturing process allows the material to be admitted or removed at the places where it is necessary. This achieves high strength and extreme light construction. With the perfection of the manufacturing technology, these frames became the best material for the frames of the bicycles at the moment.
Steel (Hi-Ten) – the advantage of the steel frames is their elasticity and low price. One drawback is their higher weight. To remedy this disadvantage, steel alloys such as Cr-Mo (refined steel with chromium and molybdenum additive) or alloys such as Columbus are often used. The hardness of the alloy allows to use thinner pipe walls, and this makes the frame lighter. Of course, the quality of these alloys also increases their price. Currently, steel is most commonly used in the production of the frames of BMX bikes, which have the maximum demands in terms of endurance and shock/fall resistance.
Individual advantages of the materials of frames:
|+ low weight||+ Strength||+ Stiffness|
|+ Stiffness||+ extremely light||+ Elasticity|
|+ good workmanship|
How to choose the right bike size
The frame size (the frame height) is the distance between the center axis and the end of the saddle tube of the frame. The size is usually expressed in inches (1 inch = 2.54 cm). Depending on the brand of the bike or the frame construction, the frame sizes may differ slightly. In order to determine the size of the bicycle frame more precisely, it is recommended to also take into account the table, which determines the frame size by the length of the lower limbs. The frame of the cross -trekking-bikes can be 1 to 2 inches larger. To choose the right bike size, use our guides for adult sizes and child sizes.
Determination of frame size by height (adults):
|Height||Mountain bikes (inches)||Cross Bikes (inch)||Road bicycles (cm)|
|150 – 155 cm||15″ – 16″||16″||50 – 52|
|155 – 160 cm||16″||16″||52|
|160 – 165 cm||16″ – 17″||17″||52|
|165 – 170 cm||17″ – 18″||17″ – 18″||52 – 54|
|170 – 175 cm||18″ – 19″||18″ – 19″||54 – 56|
|175 – 180 cm||19″ – 20″||19″ – 20″||56 – 58|
|180 – 185 cm||20″ – 21″||20″ – 21″||58 – 60|
|185 – 190 cm||21″ – 22″||21″ – 22″||60|
|190 – 195 cm||22″ – 23″||22″ – 23″||62|
|from 195||from 23″||24″||62 – 64|
Determination of the frame size by the age and height of the child:
|Diameter of the wheels||Age of the child||Body height in cm|
|12″||2 – 4||90 – 110 cm|
|14″||3 – 5||95 – 115 cm|
|16″||4 – 7||100 – 125 cm|
|20″||6 – 9||105 – 135 cm|
|24″||8 – 12||115 – 155 cm|
|26″||from 10||from 155 cm|
Determination of frame size by length of lower limbs (adults)
The frame size is determined by the length of the saddle tube, from which the other frame dimensions are derived. This size is called the “middle-middle”. The general recommendation is that the frame size of the mountain bike must be chosen so that the upper (horizontal) frame tube is about 5 cm from the step of the cyclist, who is riding over the bike. The recommended frame sizes can be found in the table below, as an orientation size also the height of the body is given.
|Sports use||Recreational use|
|161 cm||72 cm||40 cm||15.7″||42 cm||16.5″|
|165 cm||75 cm||42 cm||16.5″||44 cm||17.3″|
|169 cm||79 cm||44 cm||17.3″||46 cm||18.1″|
|173 cm||82 cm||46 cm||18.1″||48 cm||18.9″|
|179 cm||87 cm||48 cm||18.9″||50 cm||19.7″|
|183 cm||89 cm||50 cm||19.7″||52 cm||20.5″|
|187 cm||92 cm||52 cm||20.5″||54 cm||21.3″|
|193 cm||96 cm||54 cm||21.3″||56 cm||22″|
Bicycle Equipment – Component Set
Under a component set, different bicycle parts are often referred to. These are brakes, stems, pedals, seatposts, cranks, derailleurs, etc. The cheapest combination is the complete set, as no components of different levels and from different manufacturers are mixed on the bike. There is a simple rule, namely – the higher quality materials are used in the set, the higher their reliability, adjustability, useful life, but also the price. The cheapest components are often made of pressed sheet metal or plastic, the sets of the highest level are usually made of scandal, titanium and carbon. Expensive high-quality parts also help to significantly reduce the weight of the bike, which is appreciated on longer journeys.
Natural driver ergonomics – saddle position
Set the correct saddle height so that when sitting in the saddle, you can reach the pedals with the heel with stretched legs. The tip of the foot is on the pedal when driving, and the leg is slightly bent in the lower pedal position. Your pelvis should not fluctuate from left to right. The pool should therefore be almost immobile during the journey. The inclination of the saddle is adjusted according to the needs of the rider or the type of bike. For mountain bikes, cross bikes and road bikes, the horizontal position is ideal.